The United States and Japan will step up their defence cooperation to deal with the threat from nuclear-armed North Korea as tensions in East Asia remain high, officials from the two allies said on Thursday.

US condemns London mosque attack

The United States says it "strongly condemns" an attack near a mosque in London and that the attack appears to have targeted Muslim worshippers.

State Department spokeswoman Heather Nauert said on Monday that the US stands with the UK and is ready to provide any help that British officials would find helpful. She's calling the incident a "terrorist attack."

A large white van driven by a man identified as 47-year-old Darren Osborne apparently swerved into a group of Muslims who were leaving evening prayers early on Monday. At least nine people were injured.

Nauert says the US is extending sympathy to the families and communities of the victims and hopes the wounded recover quickly.

She says the US commends the first responders and the bystanders for their courage in apprehending the attacker until police arrived.

The State Department says the US and the UK remain committed to fighting "the plague of terrorism."

The White House, meanwhile, says President Donald Trump is receiving updates on the incident.